Adherent composition and method of temporarily fixing member therewith

ABSTRACT

Provided are a temporal fixation method in processing of optical members and a resin composition suitable therefor. The present invention provides a composition which is characterized by comprising (A1): a (meth)acrylate with a molecular weight of at least 500 having at least one (meth)acryloyl group at a terminal or in a side chain of a molecule, (B1): a polyfunctional (meth)acrylate, (C1): a (meth)acrylate other than (A1) and (B1), and (D1): a photopolymerization initiator. The invention also provides a method for temporarily fixing a member, characterized by comprising bonding a member to temporarily fix it with use of the composition, processing the temporarily fixed member, and immersing the processed member in warm water of at most 90° C., thereby removing a cured resin of the composition.

TECHNICAL FIELD

The present invention relates to a method for temporarily fixing amember in processing of various members, and an adhesive composition andan adhesive suitable for the fixation. More particularly, the presentinvention relates to a method for temporarily fixing an optical memberin processing the member and a photocurable adhesive suitable for theapplication.

BACKGROUND ART

Two-sided tapes and hot-melt type adhesives are used as adhesives fortemporary fixation method of optical lenses, prisms, arrays, siliconwafers, semiconductor packaging parts, and so on, and members bonded orlaminated with use of these adhesives are cut into a predeterminedshape, followed by removal of the adhesive to produce processed members.With respect to the semiconductor packaging parts, for example, they arefixed on a substrate with a two-sided tape and then cut into desiredparts, and the two-sided tape is irradiated with ultraviolet rays to beseparated from the parts. Furthermore, in the case of the hot-melt typeadhesive, members are bonded therewith and heated to let the adhesivepenetrate into their interspace, and then the members are cut intodesired parts, followed by removal of the adhesive in an organicsolvent.

However, in the case of the two-sided tape, there were problems that itwas difficult to achieve satisfactory thickness accuracy; that it wasinferior in the chipping property in processing of parts because of weakadhesive strength; that it was impossible to separate the tape withoutheating at 100° C. or more; and that, where it was separated byirradiation with ultraviolet rays, it was impossible to separate thetape if an adherend had a poor UV transmittance.

In the case of the hot-melt type adhesive, it could not be effective inbonding without heating at 100° C. or more, so that there was arestriction on the members to be used. Furthermore, it was necessary touse an organic solvent in removal of the adhesive, and washing stepswith an alkali solvent and a halogen type organic solvent werecumbersome and also problematic from the viewpoint of workingenvironments.

In order to overcome these drawbacks, there were proposals onphotocurable or heat-curable adhesives for temporary fixation methodcontaining a water-soluble compound such as a water-soluble vinylmonomer. These adhesive compositions solved the problem of theremovability in water but they still had problems that the adhesivestrength was low in fixation of parts and that the members after cut hadpoor dimensional accuracy. Furthermore, there were proposals onadhesives for temporary fixation method improved in adhesion with use ofa specific, highly hydrophilic (meth)acrylate, and, also improved inremovability by swelling and partial dissolution. However, a cuttingprocess involves generation of frictional heat between the parts and acutting jig such as a blade or a diamond cutter and thus is carried outwhile cooling the parts with a large amount of water. Therefore, a curedresin of the above highly hydrophilic composition swells to become softduring the cutting, whereby higher dimensional accuracy cannot beachieved. In addition, the cured resin dissolved in part remains as aresidual adhesive on the members after the removal, which causes aproblem in appearance (cf. Patent Documents 1, 2 and 3).

-   Patent Document 1: JP-A-06-116534-   Patent Document 2: JP-A-11-71553-   Patent Document 3: JP-A-2001-226641

DISCLOSURE OF THE INVENTION Problem to be Solved by the Invention

In order to improve the dimensional accuracy of the members aftercutting, there are desires for a photocurable adhesive hydrophobic, highin adhesive strength, excellent in removability in water, free of anadhesive residue on the members after removal, and environmentallyexcellent in working, particularly, in application fields of opticalmembers.

The inventors of the present invention have conducted extensive studiesto solve the above problems in the prior art, and as a result, havefound that an adhesive composition having a high adhesive strength and agood removability in water or in warm water is obtained with use ofspecific hydrophobic (meth)acryl monomers in combination, and that theobject of the present invention could be attained. The present inventionhas been accomplished on the basis of such a discovery.

Means for Solving the Problem

The present invention resides in the following gists.

1. A composition which is characterized by comprising (A1): a(meth)acrylate with a molecular weight of at least 500 having at leastone (meth)acryloyl group at a terminal or in a side chain of a molecule,(B1): a polyfunctional (meth)acrylate, (C1): a (meth)acrylate other thanthe above-mentioned (A1) and (E1), and (D1): a photopolymerizationinitiator (the composition will hereinafter be referred to as“Embodiment I”).2. The composition according to the above-mentioned 1, wherein (A1)comprises at least one member selected from the group consisting of apolybutadiene, a polyisoprene and their hydrogenated products.3. The composition according to the above-mentioned 1 or 2, wherein(A1), (B1) and (C1) are all hydrophobic.4. The composition according to any one of the above-mentioned 1 to 3,comprising from 5 to 80 parts by mass of (A1), from 1 to 50 parts bymass of (B1), from 5 to 80 parts by mass of (C1) and from 0.1 to 20parts by mass of (D1).5. A composition comprising (A2): a (meth)acrylate with a molecularweight of at least 500 having at least one (meth)acryloyl group at aterminal or in a side chain of a molecule, (B2): a polyfunctional(meth)acrylate, (C2): a (meth)acrylate other than the above-mentioned(A2) and (B2), (D2): a photopolymerization initiator and (E2): a polarorganic solvent (the composition will hereinafter be referred to as“Embodiment II”).6. The composition according to the above-mentioned 5, wherein (E2) isat least one member selected from the group consisting of methanol,ethanol, isopropyl alcohol and n-butanol.7. The composition according to the above-mentioned 5 or 6, wherein(A2), (B2) and (C2) are all hydrophobic.8. The composition according to any one of the above-mentioned 5 to 7,comprising from 1 to 50 parts by mass of (A2) and (B2), from 5 to 95parts by mass of (C2), from 0.1 to 20 parts by mass of (D2) and from 0.5to 10 parts by mass of (E2).9. An adhesive comprising the composition as defined in any one of theabove-mentioned 1 to 8.10. A method for temporarily fixing a member, characterized bycomprising bonding to temporarily fix the member with use of thecomposition as defined in any one of the above-mentioned 1 to 8,processing the temporarily fixed member, and immersing the processedmember in warm water of at most 90° C., thereby removing a cured resinof the composition.11. A composition comprising the following (A3), (B3) and (D3)(hereinafter referred to as “Embodiment III”):

(A3): a urethane (meth)acrylate

(B3): one or more (meth)acrylic acid derivative monomers selected fromthe group consisting of n-(meth)acryloyloxyalkyl hexahydrophthalimides,carboxyl group-containing (meth)acrylates and (meth)acrylic acidderivative monomers represented by the general formula (C3):Z—O—(R₂O)_(P)—R₁  General Formula (C3)wherein Z represents a (meth)acryloyl group, R₁ a phenyl group or aphenyl group having an alkyl group with 1 to 3 carbons, R₂—C₂H₄—,—C₃H₆—, —CH₂CH(CH₃)—, —CH₂CH(OH)CH₂—, —C₄H₈— or —C₆H₁₂—, and p aninteger of from 1 to 10.

D(3): a photopolymerization initiator

12. The composition according to the above-mentioned 11, wherein theurethane (meth)acrylate of (A3) is water-soluble.

13. An adhesive comprising the composition as defined in theabove-mentioned 11 or 12.

14. A method for temporarily fixing a member, comprising bonding themember with use of an adhesive that reduces adhesive strength throughcontact with water, curing the adhesive to temporarily fix the member,processing the temporarily fixed member, and immersing the processedmember in water, thereby removing the cured adhesive.15. A method for temporarily fixing a member, characterized bycomprising bonding the member with use of an adhesive that reducesadhesive strength through contact with water, curing the adhesive totemporarily fix the member, processing the temporarily fixed member, andimmersing the processed member in water to effect swelling thereof,thereby removing the cured adhesive in the form of a film.16. A method for temporarily fixing a member, characterized bycomprising bonding the member with use of the adhesive as defined in theabove-mentioned 13, curing the adhesive to temporarily fix the member,processing the temporarily fixed member, and immersing the processedmember in water to effect swelling thereof, thereby removing the curedadhesive in the form of a film.

Effect of the Invention

The composition of the present invention is photocurable by virtue ofits composition and is cured with visible light or ultraviolet rays.Therefore, the composition of the present invention is considerablysuperior in laborsaving, energy saving and work reduction during thebonding operation to the conventional hot-melt type adhesives.Furthermore, the cured resin of the composition shows a high adhesivestrength without being affected by cutting water or the like used inprocessing, and thus provides an effect that displacement is unlikely tooccur during processing of a member and it is thus easy to obtain themember excellent in dimensional accuracy. Furthermore, the cured resinhas a feature of reducing the adhesive strength through contact withwater, preferably with warm water of at least 30° C., particularly withwarm water of at most 90° C. to reduce the bonding strength betweenmembers or between the member and a jig, thereby facilitating recoveryof the member. As compared with the conventional adhesives, it providesan excellent effect that it is unnecessary to use an organic solventwhich is expensive, is highly combustible or generates a gas harmful tohuman bodies. Furthermore, in the case of the composition within thespecific preferred composition range, the cured resin swells throughcontact with warm water of at most 90° C., and is recovered in the formof a film from the member, thereby providing an effect of excellentworkability.

Since the temporary fixation method of the member according to thepresent invention uses the composition reducing the adhesive strengththrough contact with water, preferably with warm water of at most 90°C., or the adhesive comprising the composition, as described above, thepresent invention has the feature of capability of recovering the memberonly through contact with warm water, and, as compared with theconventional adhesives, it provides the significant effect that it isunnecessary to use an organic solvent which is expensive, is highlycombustible or generates a gas harmful to human bodies.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention includes preferred Embodiment (I), Embodiment (II)and Embodiment (III) as described below.

Embodiment (I)

Examples of the (meth)acrylate of (A1) with a molecular weight of atleast 500 having at least one (meth)acryloyl group at a terminal or in aside chain of a molecule, used in Embodiment (I), include(meth)acrylates obtained by acryloylating at least one terminal or sidechain of an oligomer/polymer with a molecular weight of at least 500,such as 1,2-polybutadiene-terminated urethane (meth)acrylates (e.g.,TE-2000 and TEA-1000 manufactured by Nippon Soda Co., Ltd.), theirhydrogenated products (e.g., TEAI-1000 manufactured by Nippon Soda Co.,Ltd.), 1,4-polybutadiene-terminated urethane (meth)acrylates (e.g.,BAC-45 manufactured by OSAKA ORGANIC CHEMICAL INDUSTRY LTD.),polyisoprene-terminated (meth)acrylates, polyester urethane(meth)acrylates, polyether urethane (meth)acrylates, polyester(meth)acrylates or bis A type epoxy(meth)acrylates (e.g., Biscoat #540manufactured by OSAKA ORGANIC CHEMICAL INDUSTRY LTD., and Biscoat VR-77manufactured by SHOWA HIGH POLYMER CO., LTD.).

(A1) preferably comprises at least one member selected from the groupconsisting of polybutadiene, polyisoprene and hydrogenated productsthereof because it enhances a property that when a cured resin of thecomposition is immersed in warm water, the cured resin is removed froman adherend (hereinafter referred to simply as “removability”).

In the present invention, an amount of the (meth)acrylate of (A1) to beadded is preferably from 5 to 80 parts by mass, particularly preferablyfrom 5 to 60 parts by mass, relative to 100 parts by mass of the totalamount of (A1), (B1) and (C1). When the amount to be added is at least 5parts by mass, the removability is sufficient and it is secure to removethe cured resin of the composition in the form of a film. On the otherhand, when the amount is at most 80 parts by mass, it is feasible toprevent increase of viscosity and reduction of workability thereby.

The (meth)acrylate of (A1) is preferably hydrophobic. If it iswater-soluble, the cured resin of the composition could swell ordissolve in part during cutting, so as to induce displacement anddegrade machining accuracy, such being undesirable. However, it can behydrophilic unless the cured resin of the composition significantlyswells or dissolves in part with water.

Examples of the polyfunctional (meth)acrylate of (B1) include thefollowing bifunctional (meth)acrylates: 1,3-butylene glycoldi(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanedioldi(meth)acrylate, 1,9-nonanediol di(meth)acrylate, neopentyl glycoldi(meth)acrylate, dicyclopentanyl di(meth)acrylate,2-ethyl-2-butyl-propanediol (meth)acrylate, neopentyl glycol-modifiedtrimethylol propane di(meth)acrylate, stearic acid-modifiedpentaerythritol diacrylate, polypropylene glycol di(meth)acrylate,2,2-bis(4-(meth)acryloxy diethoxyphenyl) propane,2,2-bis(4-(meth)acryloxy propoxyphenyl) propane,2,2-bis(4-(meth)acryloxy tetraethoxyphenyl) propane, and so on. Further,examples of (B1) include the following trifunctional (meth)acrylates:trimethylol propane tri(meth)acrylate, tris[(meth)acryloxyethyl]isocyanurate, and so on. Examples of tetrafunctional andhigher-functional (meth)acrylates include dimethylolpropanetetra(meth)acrylate, pentaerythritol tetra(meth)acrylate,pentaerythritol ethoxy tetra(meth)acrylate, dipentaerythritolpenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and so on.

An amount of the polyfunctional (meth)acrylate of (B1) to be added ispreferably from 1 to 50 parts by mass, particularly preferably from 5 to30 parts by mass, relative to 100 parts by mass of the total amount of(A1), (B1) and (C1). When the amount to be added is at least 1 part bymass, the removability is sufficient and it is secure to remove thecured resin of the composition in the form of a film. On the other hand,when the amount is at most 50 parts by mass, the initial adhesion can bemaintained well.

The polyfunctional (meth)acrylate of (B1) is more preferably hydrophobicas well as (A1) was. If it is water-soluble, the cured resin of thecomposition could swell during cutting, so as to induce displacement anddegrade machining accuracy, such being undesirable. However, it can behydrophilic unless the cured resin of the composition significantlyswells or dissolves in part with water.

Examples of the (meth)acrylate of (C1) other than said (A1) and (B1)include methyl(meth)acrylate, ethyl (meth)acrylate,propyl(meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl(meth)acrylate,isooctyl (meth)acrylate, isodecyl(meth)acrylate, lauryl (meth)acrylate,stearyl(meth)acrylate, phenyl (meth)acrylate, cyclohexyl(meth)acrylate,dicyclopentanyl(meth)acrylate, dicyclopentenyl (meth)acrylate,dicyclopentenyloxyethyl(meth)acrylate, isobornyl(meth)acrylate,methoxylated cyclodecatriene (meth)acrylate,2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate,3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl(meth)acrylate,tetrahydrofurfuryl(meth)acrylate,2-hydroxy-3-phenoxypropyl(meth)acrylate, glycidyl(meth)acrylate,caprolactone-modified tetrahydrofurfuryl(meth)acrylate,3-chloro-2-hydroxypropyl(meth)acrylate, N,N-dimethylaminoethyl(meth)acrylate, N,N-diethylaminoethyl (meth)acrylate,t-butylaminoethyl(meth)acrylate, ethoxycarbonylmethyl(meth)acrylate,phenol ethylene oxide-modified acrylate, phenol (2-mol ethyleneoxide-modified) acrylate, phenol (4-mol ethylene oxide-modified)acrylate, paracumylphenol ethylene oxide-modified acrylate, nonylphenolethylene oxide-modified acrylate, nonylphenol (4-mol ethyleneoxide-modified) acrylate, nonylphenol (8-mol ethylene oxide-modified)acrylate, nonylphenol (2.5-mol propylene oxide-modified) acrylate,2-ethylhexyl carbitol acrylate, ethylene oxide-modified phthalic acid(meth)acrylate, ethylene oxide-modified succinic acid (meth)acrylate,trifluoroethyl (meth)acrylate, acrylic acid, methacrylic acid, maleicacid, fumaric acid, ω-carboxy-polycaprolactone mono(meth)acrylate,phthalic acid monohydroxyethyl (meth)acrylate, (meth)acrylic acid dimer,β-(meth)acroyloxyethyl hydrogen succinate, n-(meth)acryloyloxyalkylhexahydrophthalimide, and so on.

An amount of the (meth)acrylate of (C1) to be added is preferably from 5to 80 parts by mass, particularly preferably from 10 to 80 parts bymass, relative to 100 parts by mass of the total amount of (A1), (B1)and (C1). When the amount to be added is at least 5 parts by mass, theinitial adhesion can be maintained well. On the other hand, when theamount is at most 80 parts by mass, the removability can be securedwell, so that the cured resin of the composition can be removed in theform of a film.

The (meth)acrylate of (C1) is more preferably hydrophobic as well as(A1) and (B1). Particularly, it is further preferred that all of (A1),(B1) and (C1) be hydrophobic. If it is water-soluble, the cured resin ofthe composition could swell during cutting, so as to induce displacementand degrade machining accuracy. This can be securely prevented by thehydrophobic (meth)acrylate. It can be hydrophilic unless the cured resinof the composition swells or dissolves in part with water.

The adhesion to a metal surface can be further improved by using thecomposition blended from said (A1), (B1) and (C1) in combination with aphosphate having a vinyl group or (meth)acryl group, such as(meth)acryloyloxyethyl acid phosphate, dibutyl 2-(meth)acryloyloxyethylacid phosphate, dioctyl 2-(meth)acryloyloxyethyl phosphate, diphenyl2-(meth)acryloyloxyethyl phosphate and (meth)acryloyloxyethylpolyethylene glycol acid phosphate.

The photopolymerization initiator of (D1) is blended in order to effectsensitization with active rays such as visible light or ultraviolet raysto enhance the photocuring property of the composition, and can be oneof various known photopolymerization initiators. Specific examples ofthe photopolymerization initiator include benzophenone and itsderivatives, benzyl and its derivatives, anthraquinone and itsderivatives, benzoin and benzoin derivatives such as, benzoin methylether, benzoin ethyl ether, benzoin propyl ether, benzoin isobutyl etherand benzyl dimethyl ketal, acetophenone derivatives such asdiethoxyacetophenone and 4-t-butyltrichloroacetophenone,2-dimethylaminoethyl benzoate, p-dimethylaminoethyl benzoate, diphenyldisulfide, thioxanthone and their derivatives, camphor quinone andcamphor quinone derivatives such as7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptane-1-carboxylic acid,7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptane-1-carboxy-2-bromoethylester,7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptane-1-carboxy-2-methyl ester and7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptane-1-carboxylic acid chloride,α-amino alkylphenone derivatives such as2-methyl-1-[4-(methylthio)phenyl]-2-morpholino propane-1-on and2-benzyl-2-dimethylamino-1-(4-morpholino phenyl)-butanone-1, and acylphosphine oxide derivatives such as benzoyl diphenyl phosphine oxide,2,4,6-trimethyl benzoyl diphenyl phosphine oxide, benzoyldiethoxyphosphine oxide, 2,4,6-trimethyl benzoyldimethoxyphenylphosphine oxide and 2,4,6-trimethyl benzoyldiethoxyphenylphosphine oxide. The photopolymerization initiators can beused alone or in combination with two or more initiators.

An amount of the photopolymerization initiator of (D1) to be added ispreferably from 0.1 to 20 parts by mass, relative to 100 parts by massof the total amount of (A1), (B1) and (C1). The amount is morepreferably from 3 to 20 parts by mass. When the amount is at least 0.1part by mass, it is sure to achieve the effect of promoting the curing.On the other hand, when the amount is at most 20 parts by mass, asufficient curing rate can be assured. A more preferred embodiment issuch that (D1) is added by at least 3 parts by mass, which is furtherpreferred in that the composition becomes curable regardless of an lightirradiation amount, a crosslinking degree of the cured resin of thecomposition becomes higher, no displacement occurs during cutting, andthe removability is improved.

In order to improve the storage stability, the composition according tothe present invention can contain a small amount of a polymerizationinhibitor. Examples of the polymerization inhibitor include methylhydroquinone, hydroquinone, 2,2-methylene-bis(4-methyl-6-tertiary-butylphenol), catechol, hydroquinone monomethyl ether, monotertiarybutylhydroquinone, 2,5-ditertiary butylhydroquinone, p-benzoquinone,2,5-diphenyl-p-benzoquinone, 2,5-ditertiary-butyl-p-benzoquinone, picricacid, citric acid, phenothiazine, tertiary-butyl catechol,2-butyl-4-hydroxy anisole, 2,6-ditertiary-butyl-p-cresol, and so on.

An amount of the polymerization inhibitor to be used is preferably from0.001 to 3 parts by mass, more preferably from 0.01 to 2 parts by mass,relative to 100 parts by mass of the total amount of (meth)acrylates(A1), (B1) and (C1). When the amount is at least 0.001 part by mass, thestorage stability can be secured. On the other hand, when the amount isat most 3 parts by mass, good adhesion can be obtained and thecomposition can be prevented from being uncured.

The composition of the present invention may contain an additive such asan elastomer selected from various ones, e.g., acryl rubber, urethanerubber and acrylonitrile-butadiene-styrene rubber, an inorganic filler,a solvent, an extender, a reinforcing material, a plasticizer, athickener, a dye, a pigment, a flame retardant, a silane coupling agentor a surfactant as long as it does not impair the object of the presentinvention.

The temporary fixation of the present invention is a method fortemporarily fixing a member, which comprises bonding the member with useof the above composition, curing the composition to temporarily fix themember, processing the temporarily fixed member and immersing theprocessed member in warm water to remove the cured composition. Byvirtue of the method, various members such as optical members can beprocessed with high machining accuracy, without use of an organicsolvent.

According to a preferred embodiment of the present invention, the curedresin is brought into contact with warm water of at most 90° C. inremoval of the composition to swell and is removed in the form of a filmfrom the member, thereby obtaining an effect of excellent workability.

In the temporary fixation method of the present invention, it ispreferred to use an adhesive comprising the composition of the presentinvention, because the above effect of the invention can be certainlyobtained.

In the present invention, use of warm water appropriately heated to atmost 90° C. is preferred in terms of productivity because thesatisfactory removability is achieved in a short period of time. Withrespect to the above-mentioned temperature of the warm water, it ispreferred to use warm water of from 30° C. to 80° C., preferably from40° C. to 80° C. because the cured resin of the composition becomesswollen in a short period of time and the residual stress in curing ofthe composition is released to reduce the adhesive strength, therebyenabling the cured resin of the composition to be removed in the form ofa film. A recommendable method for bringing the cured resin into contactwith the warm water is a method of immersing the whole of the bondedmember in the warm water, which is simple.

In the present invention, there are no particular restrictions on amaterial of the member to be temporarily fixed, and in a case where theadhesive is an ultraviolet-curable adhesive, the member is preferablyone made of a UV transmitting material. Examples of the material includecrystalline quartz members, glass members and plastic members, and thusthe temporary fixation method of the present invention can be applied totemporary fixation in processing of crystal oscillators, glass lenses,plastic lenses and optical disks.

With respect to how to use the adhesive in the temporary fixationmethod, assuming that the adhesive is a photocurable one, the followingmethod can be adopted: the adhesive is first applied e.g., by a methodof applying an appropriate amount of the adhesive onto a bonding surfaceof a member to be fixed or a support substrate, and then placing anothermember thereon, or a method of preliminarily stacking multiple membersto be temporarily fixed, and letting the adhesive penetrate into theirinterspace to be applied, and thereafter the members are exposed tovisible light or ultraviolet rays to cure the photocurable adhesive totemporarily fix the members.

Thereafter, the temporarily fixed members are subjected to processingsuch as cutting, grinding, polishing or drilling into a desired shape,and then the members are immersed in warm water, whereby the cured resinof the composition can be removed from the members.

Embodiment (II)

The (meth)acrylate of (A2) with a molecular weight of at least 500having at least one (meth)acryloyl group at a terminal or in a sidechain of a molecule, used in this Embodiment (II), can be one selectedfrom the compounds exemplified as the component (A1) used in the aboveEmbodiment (I). Thus, exemplification is omitted here.

(A2) preferably comprises at least one member selected from the groupconsisting of polybutadiene, polyisoprene and hydrogenated productsthereof because it enhances the property that when a cured resin of thecomposition is immersed in warm water, the cured resin is removed froman adherend (removability).

In the present invention, an amount of the (meth)acrylate of (A2) to beadded is preferably from 1 to 50 parts by mass, particularly preferablyfrom 5 to 45 parts by mass, relative to 100 parts by mass of the totalamount of (A2), (B2) and (C2). When the amount to be added is at least 1part by mass, the removability is sufficient and it is secure to removethe cured resin of the composition in the form of a film. On the otherhand, when the amount is at most 50 parts by mass, the initial adhesioncan be maintained well.

The (meth)acrylate of (A2) is preferably hydrophobic. If it iswater-soluble, the cured resin of the composition could swell ordissolve in part during cutting, so as to induce displacement anddegrade machining accuracy, such being undesirable. However, it can behydrophilic unless the cured resin of the composition significantlyswells or dissolves in part with water.

The polyfunctional (meth)acrylate of (B2) to be used, can be oneselected from the compounds exemplified as the component (B1) used inthe above Embodiment (I), i.e., the compounds exemplified as theexamples of the bifunctional (meth)acrylates, trifunctional(meth)acrylates and tetra- and higher-functional (meth)acrylates. Thus,exemplification is omitted here.

An amount of the polyfunctional (meth)acrylate of (B2) to be added ispreferably from 1 to 50 parts by mass, particularly preferably from 5 to40 parts by mass, relative to 100 parts by mass of the total amount of(A2), (B2) and (C2). When the amount to be added is at least 1 part bymass, the removability is sufficient and it is secure to remove thecured resin of the composition in the form of a film. On the other hand,when the amount is at most 50 parts by mass, the initial adhesion can bemaintained well.

The polyfunctional (meth)acrylate of (B2) is more preferably hydrophobicas (A2) was. If it is water-soluble, the cured resin of the compositioncould swell during cutting, so as to induce displacement and degrade themachining accuracy, such being undesirable. However, it can behydrophilic unless the cured resin of the composition significantlyswells or dissolves in part with water.

The (meth)acrylate monomer of (C2) to be used may be one selected fromthe compounds as exemplified as the component (C1) used in the aboveEmbodiment (I). Thus, exemplification is omitted here.

An amount of the (meth)acrylate of (C2) to be added is preferably from 5to 95 parts by mass, particularly preferably from 10 to 80 parts bymass, relative to 100 parts by mass of the total amount of (A2), (B2)and (C2). When the amount to be added is at least 5 parts by mass, theinitial adhesion can be maintained well. On the other hand, when theamount is at most 95 parts by mass, the removability can be securedwell, so that the cured resin of the composition can be removed in theform of a film.

The (meth)acrylate of (C2) is more preferably hydrophobic as well as(A2) and (B2). Particularly, it is further preferred that all of (A2),(B2) and (C2) be hydrophobic. If it is water-soluble, the cured resin ofthe composition could swell during cutting, so as to induce displacementand degrade machining accuracy. This can be securely prevented by thehydrophobic (meth)acrylate. It can be hydrophilic, unless the curedresin of the composition swells or dissolves in part with water.

The adhesion to a metal surface can be further improved by using thecomposition blended from said (A2), (B2) and (C2) in combination with aphosphate having a vinyl group or (meth)acryl group, such as(meth)acryloyloxyethyl acid phosphate, dibutyl 2-(meth)acryloyloxyethylacid phosphate, dioctyl 2-(meth)acryloyloxyethyl phosphate, diphenyl2-(meth)acryloyloxyethyl phosphate and (meth)acryloyloxyethylpolyethylene glycol acid phosphate.

The photopolymerization initiator of (D2) is blended in order to effectsensitization with active rays such as visible light or ultraviolet raysto enhance photocuring property of the composition, and can be one ofvarious known photopolymerization initiators. Specific examples includethe compounds as exemplified as the photopolymerization initiator of(D1) used in the above Embodiment (I). Thus, exemplification is omittedhere. The photopolymerization initiators can be used alone or incombination with two or more initiators.

An amount of the photopolymerization initiator of (D2) to be added ispreferably from 0.1 to 20 parts by mass relative to 100 parts by mass ofthe total amount of (A2), (B2) and (C2). The amount is more preferablyfrom 3 to 20 parts by mass. When the amount is at least 0.1 part bymass, it is sure to achieve the effect of promoting the curing. On theother hand, when the amount is at most 20 parts by mass, a sufficientcuring rate can be assured. A more preferred embodiment is such that(D2) is added by at least 3 parts by mass, which is further preferred inthat the composition becomes curable regardless of an light irradiationamount, a crosslinking degree of the cured resin of the compositionbecomes high, no displacement occurs during cutting, and theremovability is improved.

The present invention is characterized in that the polar organic solventof (E2) is used in combination with (A2), (B2) and (C2), and this cansurely develop the phenomenon in which the composition after curedreadily swells through contact with warm water to reduce the adhesivestrength.

The polar organic solvent of (E2) preferably has a boiling point of from50° C. to 130° C. When the polar organic solvent is selected as one witha boiling point within the above range, it can more securely develop thephenomenon in which the composition after cured decreases the adhesivestrength through contact with warm water, such being undesirable.Furthermore, the polar organic solvent may be one selected, for example,from alcohols, ketones, esters, and so on, and among those, an alcoholis preferably selected according to the Inventor's research result.

Examples of the alcohol include methanol, ethanol, n-propanol,isopropanol, n-butanol, isobutanol, secondary butanol, tertiary butanol,n-amyl alcohol, isoamyl alcohol, 2-ethylbutyl alcohol, and so on.Furthermore, alcohols preferably applicable among the above alcohols aremethanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol,secondary butanol and tertiary butanol with a boiling point of at most120° C., and further preferred alcohols among them are methanol,ethanol, isopropanol and n-butanol.

An amount of the polar organic solvent of (E2) to be added is preferablyfrom 0.5 to 10 parts by mass relative to 100 parts by mass of the totalamount of (A2), (B2) and (C2). When the amount is at least 0.5 part bymass, the removability can be secured well. On the other hand, when theamount is at most 10 parts by mass, the initial adhesion can bemaintained well and the cured resin of the composition can be removed inthe form of a film.

The composition according to the present invention can contain a smallamount of a polymerization inhibitor in order to improve the storagestability. Specific examples of the polymerization inhibitor to be usedinclude the compounds as exemplified as the polymerization inhibitorused in the above Embodiment (I). Thus, exemplification is omitted here.

An amount of the polymerization inhibitor to be used is preferably from0.001 to 3 parts by mass, more preferably from 0.01 to 2 parts by mass,relative to 100 parts by mass of the total amount of (A2), (B2) and(C2). When the amount is at least 0.001 part by mass, the storagestability can be secured. On the other hand, when the amount is at most3 parts by mass, good adhesion can be obtained and the composition canbe prevented from being uncured.

The composition of the present invention may contain an additivegenerally used, such as an elastomer selected from various ones, e.g.,acryl rubber, urethane rubber, and acrylonitrile-butadiene-styrenerubber, an inorganic filler, a solvent, an extender, a reinforcingmaterial, a plasticizer, a thickener, a dye, a pigment, a flameretardant, a silane coupling agent or a surfactant as long as it doesnot impair the object of the present invention.

Further, the present invention provides a method for temporarily fixinga member, which comprises bonding the member with use of a compositionreducing its adhesive strength through contact with warm water of atmost 90° C.; curing the composition to temporarily fix the member;processing the temporarily fixed member; and immersing the processedmember in warm water to remove the cured adhesive. By this method,various members such as optical members can be processed with highmachining accuracy, without use of an organic solvent.

Furthermore, according to a preferred embodiment of the presentinvention, the cured resin is brought into contact with warm water of atmost 90° C. in removal of the composition to swell and is removed in theform of a film from the member, thereby obtaining an effect of excellentworkability.

In the temporary fixation method of the present invention, the effect ofthe above embodiment can be certainly obtained by using an adhesivecomprising the composition of the present invention.

In the present invention, use of warm water appropriately heated,specifically warm water of at most 90° C., is preferred in terms ofproductivity because the removability in water achieved in a shortperiod of time. With respect to the above-mentioned temperature of warmwater, it is preferred to use warm water of from 30° C. to 90° C.,preferably from 40° C. to 90° C., because the cured resin of theadhesive becomes swollen in a short period of time, the residual stressin curing of the composition is released to reduce the adhesivestrength, and vapor pressure of the polar organic solvent of (E2) servesas removal force between the member and the cured resin of thecomposition, thereby enabling the cured resin of the adhesive to beremoved in the form of a film from the adherend. A recommendable methodfor bringing the cured resin into contact with the water is a method ofimmersing the whole of the bonded member in the water, which is simple.

In the present invention, there are no particular restrictions on amaterial of the member to be temporarily fixed, and in a case where theadhesive is an ultraviolet-curable adhesive, the member is preferablyone made of a UV transmitting material. Examples of the material includecrystalline quartz members, glass members and plastic members, and thusthe temporary fixation method of the present invention can be applied totemporary fixation in processing of crystal oscillators, glass lenses,plastic lenses and optical disks.

With respect to how to use the adhesive in the temporary fixationmethod, assuming that the adhesive is a photocurable one, the followingmethod can be adopted: the adhesive is first applied by e.g., a methodof applying an appropriate amount of the adhesive onto a bonding surfaceof a member to be fixed or a support substrate, and then placing anothermember thereon, or a method of preliminarily stacking multiple membersto be temporarily fixed, and letting the adhesive penetrate into theirinterspace to be applied, and thereafter the members are exposed tovisible light or ultraviolet rays to cure the photocurable adhesive totemporarily fix the members.

Thereafter, the temporarily fixed members are subjected to processingsuch as cutting, grinding, polishing or drilling into a desired shape,and then the members are immersed in water, preferably in warm water,whereby the cured resin of the adhesive can be removed from the members.

Embodiment (III)

Embodiment (III) employs the urethane (meth)acrylate of (A3) as one ofits components. The urethane (meth)acrylate of (A3) used in the presentinvention is obtained by reaction of a polyisocyanate, a polyol, and a(meth)acrylic acid.

Examples of the polyisocyanate include 2,4-tolylene diisocyanate,2,6-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate,m-phenylene diisocyanate, xylylene diisocyanate, tetramethylenediisocyanate, hexamethylene diisocyanate, lysine diisocyanate ester,1,4-cyclohexylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate,3,3′-dimethyl-4,4′-biphenylene diisocyanate, and so on. They can be usedsingly or in combination with at least two kinds.

Examples of the polyol include polyester diol, polyether diol,polycaprolactone diol, polycarbonate diol, and so on.

Furthermore, the above-mentioned urethane (meth)acrylate to be used canalso be a water-soluble one, and it is preferably selected in order toattain the object of the present invention.

An amount of the urethane (meth)acrylate of (A3) to be added ispreferably from 5 to 80 parts by mass, particularly preferably from 5 to50 parts by mass, relative to 100 parts by mass of the total amount of(A3) and (B3). When the above amount is at least 5 parts by mass, goodadhesion can be secured. On the other hand, when the amount is at most80 parts by mass, it can prevent the viscosity from unnecessarilyincreasing to reduce the workability.

The present invention employs as the component (B3), at least one(meth)acrylic acid derivative monomer selected from the group consistingof n-(meth)acryloyloxyalkyl hexahydrophthalimides, carboxylgroup-containing (meth)acrylates and (meth)acrylic acid derivativemonomers represented by the general formula (C3):Z—O—(R₂O)_(P)—R₁  General Formula (C3)

wherein Z represents a (meth)acryloyl group, R₁ a phenyl group or aphenyl group having an alkyl group with 1 to 3 carbon atoms, R₂—C₂H₄—,—C₃H₆—, —CH₂CH(CH₃)—, —CH₂CH(OH)CH₂—, —C₄H₈— or —C₆H₁₂—, and p aninteger of from 1 to 10.

In the present invention, when used together with the above (A3), (B3)can provide an adhesive with high adhesive strength and the property ofreducing the adhesive strength of the cured resin through contact withwater.

Examples of the n-(meth)acryloyloxyalkyl hexahydrophthalimide includen-(meth)acryloyloxyethyl hexahydrophthalimide, n-(meth)acryloyloxypropylhexahydrophthalimide, n-(meth)acryloyloxybutyl hexahydrophthalimide, andso on.

In a case where n-(meth)acryloyloxyalkyl hexahydrophthalimide isselected as the component (B3), the content thereof is preferably from10 to 60 parts by mass, particularly preferably from 20 to 60 parts bymass, relative to 100 parts by mass of the total amount of (A3) and(B3). When the amount to be added is at least 10 parts by mass, thesatisfactory adhesive strength can be secured in bonding of a member.When it is at most 60 parts by mass, the removability of the cured resincan be secured when immersed in water.

Furthermore, the present invention permits a carboxyl group-containing(meth)acrylate to be selected as the component (B3).

Examples of the carboxyl group-containing (meth)acrylate include acrylicacid, methacrylic acid, maleic acid, fumaric acid,ω-carboxy-polycaprolactone mono(meth)acrylate, phthalic acidmonohydroxyethyl (meth)acrylate, (meth)acrylic acid dimer,β-(meth)acroyloxyethyl hydrogen succinate, and so on.

When the carboxyl group-containing (meth)acrylate is used, an amount tobe added is preferably from 1 to 50 parts by mass, particularlypreferably from 5 to 40 parts by mass, relative to 100 parts by mass ofthe total amount of (A3) and (B3). When the amount is at least 1 part bymass, the adhesion can be surely secured well. On the other hand, whenthe amount is at most 50 parts by mass, the removability in water can besecured well.

In addition, the present invention can select the (meth)acrylic acidderivative monomer having the structure of the general formula (C3) asthe component (B3):Z—O—(R₂O)_(P)—R₁  General Formula (C3)

wherein Z represents a (meth)acryloyl group, R₁ a phenyl group or aphenyl group having an alkyl group with 1 to 3 carbon atoms, R₂—C₂H₄—,—C₃H₆—, —CH₂CH(CH₃)—, —CH₂CH(OH)CH₂—, —C₄H₈— or —C₆H₁₂—, and p aninteger of from 1 to 10.

Examples of the (meth)acrylic acid derivative monomer having thestructure of the general formula (C3) includephenoxyethyl(meth)acrylate, phenoxy diethylene glycol (meth)acrylate,phenoxy polyethylene glycol (meth)acrylate, phenoxypropyl(meth)acrylate,2-hydroxy-3-phenoxy propyl(meth)acrylate, phenoxy dipropylene glycol(meth)acrylate, phenoxy polypropylene glycol (meth)acrylate, and so on.

An amount of the (meth)acrylic acid derivative monomer having thestructure of the general formula (C3) to be added is preferably from 10to 80 parts by mass, particularly preferably from 10 to 70 parts bymass, relative to 100 parts by mass of the total amount of (A3) and(B3). When the amount is at least 10 parts by mass, the high adhesioncan be secured well; and when the amount is at most 80 parts by mass,the removability in water can be secured well.

The adhesion to a metal surface can be further improved by using thecomposition of said (A3) and (B3) in combination with a phosphate havinga vinyl group or (meth)acryl group, such as (meth)acryloyloxyethyl acidphosphate, dibutyl 2-(meth)acryloyloxyethyl acid phosphate, dioctyl2-(meth)acryloyloxyethyl phosphate, diphenyl 2-(meth)acryloyloxyethylphosphate and (meth)acryloyloxyethyl polyethylene glycol acid phosphate.

In the present invention, the photopolymerization initiator of (D3) isadded to the above components (A3) and (B3). This provides thecomposition with the photocurable property in addition to the highadhesive strength and the property of reducing the adhesive strength ofthe cured resin through contact with water, whereby the presentinvention can provide an adhesive suitably applicable to opticalmembers.

The photopolymerization initiator of (D3) is blended in order to effectsensitization with active rays such as visible light or ultraviolet raysto enhance photocuring property of the resin composition, and can be oneof various known photopolymerization initiators. Specific examplesinclude the compounds as exemplified as the photopolymerizationinitiator of (D1) to be used in the above Embodiment (I). Thus,exemplification is omitted here. The photopolymerization initiators canbe used alone or in combination with two or more initiators.

An amount of the photopolymerization initiator of (D3) to be added ispreferably from 0.1 to 20 parts by mass, particularly preferably from0.5 to 15 parts by mass, relative to 100 parts by mass of the total of(A3) and (B3). When the above-mentioned amount is at least 0.1 part bymass, the effect of promoting curing can result. On the other hand, whenthe amount is at most 20 parts by mass, a sufficient curing rate can beachieved.

The composition of the present invention can contain a small amount of apolymerization inhibitor in order to improve the storage stability.Specific examples of the polymerization inhibitor to be used include thecompounds as exemplified as the polymerization inhibitor to be used inthe above Embodiment (I). Thus, exemplification is omitted here.

An amount of the polymerization inhibitor to be used is preferably from0.001 to 3 parts by mass, more preferably from 0.01 to 2 parts by mass,relative to 100 parts by mass of the total amount of (A3) and (B3). Whenthe amount is at least 0.001 part by mass, the storage stability can besecured. On the other hand, when the amount is at most 3 parts by mass,the composition can be prevented from being uncured and good adhesioncan be obtained.

The composition of the present invention may contain an additivegenerally used such as an elastomer selected from various ones, e.g.,acryl rubber, urethane rubber, and acrylonitrile-butadiene-styrenerubber, an inorganic filler, a solvent, an extender, a reinforcingmaterial, a plasticizer, a thickener, a dye, a pigment, a flameretardant, a silane coupling agent or a surfactant as long as it doesnot impair the object of the present invention.

Further, the present invention provides a method for temporarily fixinga member, which comprises bonding the member with use of an adhesivereducing its adhesive strength through contact with water, particularlywith warm water at least 30° C.; curing the adhesive to temporarily fixthe members; processing the temporarily fixed member; and immersing theprocessed member in warm water to remove the cured adhesive. By thismethod, various members such as optical members can be processed withhigh machining accuracy, without use of an organic solvent.

Furthermore, according to a preferred embodiment of the presentinvention, the cured resin is brought into contact with water in removalof the adhesive to swell and is removed in the form of a film from themember, thereby obtaining an effect of excellent workability.

In the temporary fixation of the present invention, the effect of theabove invention can be certainly obtained by using an adhesivecomprising the composition of the present invention, such beingpreferred.

In the present invention, there is no problem that the temperature ofwater is usually at room temperature, but use of warm waterappropriately heated is preferred in terms of productivity because thesatisfactory removability in water is achieved in a short period oftime. With respect to the above-mentioned temperature of the warm water,it is preferred to use warm water of from 30° C. to 90° C., preferablyfrom 40° C. to 80° C. because the cured resin of the adhesive becomesswollen in a short period of time to reduce the adhesive strength,thereby enabling the cured resin of the adhesive to be removed in theform of a film. Furthermore, a recommendable method for bringing thecured resin into contact with the water is a method of immersing thewhole of the bonded member in water, which is simple.

In the present invention, there are no particular restrictions on amaterial of the member to be temporarily fixed, and in a case where theadhesive is an ultraviolet-curable adhesive, the member is preferablyone made of a UV transmitting material. Examples of the material includecrystalline quartz members, glass members and plastic members, and thusthe temporary fixation method of the present invention can be applied totemporary fixation in processing of crystal oscillators, glass lenses,plastic lenses and optical disks.

With respect to how to use the adhesive in the temporary fixationmethod, assuming that the adhesive is a photocurable one, the followingmethod can be adopted: the adhesive is first applied e.g., by a methodof applying an appropriate amount of the adhesive onto a bonding surfaceof a member to be fixed or a support substrate, and then placing anothermember thereon, or a method of preliminarily stacking multiple membersto be temporarily fixed, and letting the adhesive penetrate into theirinterspace to be applied, and thereafter the members are exposed tovisible light or ultraviolet rays to cure the photocurable adhesive totemporarily fix the members.

Thereafter, the temporarily fixed members are subjected to processingsuch as cutting, grinding, polishing or drilling into a desired shape,and then the members are immersed in water, preferably in warm water,whereby the cured resin of the adhesive can be removed from the members.

EXAMPLES

Now, the present invention will be described in detail with reference toExamples and Comparative Examples, but it should be understood that thepresent invention is by no means restricted to such Examples. Evaluationmethods used in Examples below are as follows.

Evaluation Methods

Tensile Shear Bond Strength: the strength was measured in accordancewith JIS K 6850. Specifically, Pyrex (registered trademark for heatresistant glass manufactured by Corning Incorporated) glass (25 mmlength×25 mm width×2.0 mm thickness) was used as an adherend, and twosheets of the Pyrex glass were bonded in a bonding area with a diameterof 8 mm with a composition prepared. Then, the composition was cured bya curing apparatus using an electrodeless discharge lamp, manufacturedby Fusion UV Systems Inc., under a condition of an accumulated quantityof light of 2000 mJ/cm² at a wavelength of 365 nm, thereby preparing atest piece for tensile shear bond strength. The test piece thus preparedwas subjected to measurement of tensile shear bond strength by means ofa universal testing machine under a temperature of 23° C. and a humidityof 50% at a pulling rate of 10 mm/min.

Removing Test: a test piece for the removing test was prepared by curingthe composition in the same condition as above except that thecomposition prepared was applied onto the above Pyrex glass and bondedto a blue sheet glass (150 mm length×150 mm width×1.7 mm thickness) as asubstrate. The test piece obtained was immersed in warm water (80° C.),a period of time to removal of the Pyrex glass was measured, and aremoval state thereof was also observed.

Example 1-1

A composition was prepared by adding 10 parts by mass of benzyl dimethylketal (hereinafter abbreviated as “BDK”) as the photopolymerizationinitiator of (D1) and 0.1 part by mass of2,2-methylene-bis(4-methyl-6-tertiary butyl phenol) (hereinafterabbreviated as “MDP”) as a polymerization inhibitor to a total amount of100 parts by mass consisting of 20 parts by mass of1,2-polybutadiene-terminated urethane methacrylate (TE-2000 manufacturedby Nippon Soda Co., Ltd., hereinafter abbreviated as “TE-2000”) as the(meth)acrylate of (A1) with the molecular weight of at least 500 havingat least one (meth)acryloyl group at a terminal or in a side chain of amolecule, 15 parts by mass of dicyclopentanyl diacrylate (KAYARA D R-684manufactured by Nippon Kayaku Co., Ltd., hereinafter abbreviated as“R-684”) as the polyfunctional (meth)acrylate of (B1), 40 parts by massof n-acryloyloxyethyl hexahydrophthalimide (TO-1429 manufactured byTOAGOSEI CO., LTD., hereinafter abbreviated as “TO-1429”) as the(meth)acrylate of (C1) other than (A1) and (B1) and 25 parts by mass ofphenoxy ethyl acrylate (Light Acrylate PO-A manufactured by KyoeishaChemical Co., Ltd., hereinafter abbreviated as “PO-A”). The measurementof tensile shear bond strength and the removing test were carried outusing the composition prepared. Table 1-1 shows the results of thosetests.

TABLE 1-1 Example No. 1-1 1-2 1-3 1-4 1-5 1-6 1-7 1-8 1-9 1-10 1-11 (A1)component (parts by mass) TE-2000 20 20 20 35 50 20 20 20 20 20 TEA-100020 (B1) component (parts by mass) R-684 15 15 15 15 15 5 15 15 15 TMPTA15 NPA 15 (C1) component (parts by mass) TO-1429 40 40 40 25 40 25 40 4040 40 40 PO-A 25 25 25 25 10 M-101A 25 25 25 25 25 25 (D1)photopolymerization initiator (parts by mass) BDK 10 5 1.5 10 10 10 1010 TPO 2 I-907 2 6 Polymerization inhibitor (part by mass) MDP 0.1 0.10.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 Adhesive strength (MPa) 11.7 12.612.4 11.8 10.1 15.1 9.0 9.8 13.3 9.8 11.3 Period to removal in warm 3030 153 20 34 97 41 30 166 131 41 water at 80° C. (min) Removed state*)film film film film film film film film film film film form form formform form form form form form form form *)Film form: a cured resin of acomposition removed in the form of a film with no adhesive residue, froma surface of glass.

Examples 1-2 to 1-11

Compositions were prepared in the same manner as in Example 1-1 exceptthat raw materials of types as identified in Table 1-1 were used incompositions as identified in Table 1-1. The measurement of tensileshear bond strength and the removing test were carried out in the samemanner as in Example 1-1, using the compositions prepared. Table 1-1shows the results of those.

Materials Used

TEA-1000: 1,2-polybutadiene-terminated urethane acrylate (TEA-1000manufactured by Nippon Soda Co., Ltd.)

TMPTA: trimethylol propane triacrylate (KAYARAD TMPTA manufactured byNippon Kayaku Co., Ltd.)

NPA: neopentyl glycol diacrylate (Light Acrylate NP-A manufactured byKyoeisha Chemical Co., Ltd.)

M-101A: phenol 2-mol ethylene oxide-modified acrylate (ARONIX M-101Amanufactured by TOAGOSEI CO., LTD.)

TPO: 2,4,6-trimethyl benzoyl diphenyl phosphine oxide (Lucirin TPOmanufactured by BASF)

I-907: 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino propan-1-on(IRGACURE907 manufactured by Ciba Specialty Chemicals K.K.)

Comparative Examples 1-1 to 1-4

Compositions were prepared in the same manner as in Example 1-1 exceptthat raw materials of types as identified in Table 1-2 were used incompositions as identified in Table 1-2. The measurement of tensileshear bond strength and the removing test were carried out in the samemanner as in Example 1-1 for the compositions prepared. Table 1-2 showsthe results of those.

TABLE 1-2 Comparative example No. 1-1 1-2 1-3 1-4 (A1)component (partsby mass) TE-2000 20 0 (B1)component (parts by mass) R-684 0 0(C1)component (parts by mass) TO-1429 40 60 PO-A 40 40 Other components(parts by mass) MTEGMA 70 Acryloyl morpholine 100 30(D1)photopolymerization initiator (parts by mass) BDK 10 10 1.5 TPO 2.0Polymerization inhibitor (part by mass) MDP 0.1 0.1 0.1 0.1 Adhesivestrength (MPa) 18.6 9.8 2.0 8.4 Period to removal in not not 30 60 warmwater at 80° C. removed removed (min) Removed state**) adhesive adhesiveresidue residue **)Adhesive residue: a cured resin of a compositionremained on a surface of glass, though glass was separated.Material Used

MTEGMA: methoxy tetraethylene glycol monomethacrylate (NK Ester M-90Gmanufactured by SHIN NAKAMURA CHEMICAL CO., LTD.)

Example 1-12

The measurement of tensile shear bond strength and the removing testwere carried out in the same manner as in Example 1-1 except that thetest pieces for the removing test and for the measurement of tensileshear bond strength were prepared in such a manner that the compositionswere made by different amounts of the photopolymerization initiator (D1)in Examples 1-1, 1-2 and 1-11 and they were used and cured by means of acuring apparatus using an electrodeless discharge lamp, manufactured byFusion UV Systems Inc. under different accumulated light quantities of200, 500, 1000 and 4000 mJ/cm² at a wavelength of 365 nm. As a result,each composition maintained good adhesive strength in each accumulatedquantity of light and showed good removability. Table 1-3 shows theresults of those.

TABLE 1-3 Accumulated irradiation amount Example No. (mJ/cm²) 1-1 1-21-11 200 Adhesive 9.8 10.5 9.8 strength (MPa) Period to 73 79 45 removal(min) 500 Adhesive 11.3 13.7 11.3 strength (MPa) Period to 76 130 35removal (min) 1000 Adhesive 13.6 14.6 11.3 strength (MPa) Period to 53150 25 removal (min) 4000 Adhesive 10.9 10.0 10.6 strength (MPa) Periodto 35 88 66 removal (min)

Example 1-13

Pyrex glass with 150 mm length×150 mm width×2 mm thickness and the bluesheet glass used in Example 1-1 as dummy glass were bonded with thecomposition prepared in Example 1-1 and the composition was cured in thesame manner as in Example 1-1. Only the heat-resistant Pyrex glassportion of the adhesive test piece was cut in the size of 10 mm squareby means of a dicing apparatus. Neither dropout nor loss of the Pyrexglass occurred during cutting, so as to demonstrate satisfactoryprocessability with good chipping resistance. The adhesive test piecewith the Pyrex glass portion only being cut was immersed in warm waterat 80° C. and the entire adhesive was removed in 120 minutes.

Example 2-1

A composition was prepared by adding 2 parts by mass of isopropylalcohol (hereinafter abbreviated as “IPA”) as the polar organic solventof (E2), 10 parts by mass of BDK as the photopolymerization initiator of(D2) and 0.1 part by mass of MDP as a polymerization inhibitor to thetotal amount of 100 parts by mass consisting of 20 parts by mass ofTE-2000 as the (meth)acrylate of (A2) with a molecular weight of atleast 500 having at least one (meth)acryloyl group at a terminal or in aside chain of the molecule, 15 parts by mass of R-684 as thepolyfunctional (meth)acrylate of (B2), 40 parts by mass of TO-1429 asthe monofunctional (meth)acrylate of (C2) other than (A2) and (B2) and25 parts by mass of M-101A. The measurement of tensile shear bondstrength and the removing test were carried out using the compositionprepared. Table 2-1 shows the results of those.

TABLE 2-1 Example No. 2-1 2-2 2-3 2-4 2-5 2-6 2-7 2-8 2-9 2-10 2-11 (A2)component (parts by mass) TE-2000 20 20 20 20 20 20 20 20 20 20 20 (B2)component (parts by mass) R-684 15 15 15 15 15 15 15 15 15 15 15 (C2)component (parts by mass) TO-1429 40 40 40 40 40 40 40 40 40 40 40M-101A 25 25 25 25 25 25 25 25 25 25 25 (E2) component IPA (b.p. 82° C.)2 0.5 4 6 2 2 2 2 Ethanol(b.p. 78° C.) 2 Methanol (b.p. 65° C.) 2n-Butanol 2 (b.p. from 83 to 118° C.) (D2) photopolymerization initiator(parts by mass) BDK 10 10 10 10 10 10 10 5 1.5 TPO 2 I-907 2Polymerization inhibitor (part by mass) MDP 0.1 0.1 0.1 0.1 0.1 0.1 0.10.1 0.1 0.1 0.1 Adhesive strength (MPa) 11.6 11.2 12.0 9.8 14.0 10.6 9.613.3 11.7 12.4 10.2 Period to removal in 20 25 22 32 44 16 10 44 79 4875 warm water at 80° C. (min) Removed state*) film film film film filmfilm film film film film film form form form form form form form formform form form *)Film form: a cured resin of a composition removed inthe form of a film with no adhesive residue, from a surface of glass.

Examples 2-2 to 2-21

Compositions were prepared in the same manner as in Example 2-1 exceptthat raw materials of types as identified in Table 2-1 and Table 2-2were used in compositions as identified in Table 2-1 and Table 2-2. Themeasurement of tensile shear bond strength and the removing test werecarried out in the same manner as in Example 2-1, using the compositionsprepared. Table 2-1 and Table 2-2 show the results of those.

TABLE 2-2 Example No. 2-12 2-13 2-14 2-15 2-16 2-17 2-18 2-19 2-20 2-21(A2) component (parts by mass) TE-2000 20 20 20 20 10 10 0 0 20 35 (B2)component (parts by mass) R-684 15 15 15 5 25 5 25 5 15 35 (C2)component (parts by mass) TO-1429 40 40 40 40 40 40 40 40 40 15 QM 25M-101A 25 15 BZ 25 35 25 45 35 55 IBX 25 (E2) component (parts by mass)IPA (b.p. 82° C.) 2 2 2 2 2 2 2 2 12 2 (D2) photopolymerizationinitiator (parts by mass) BDK 5 5 5 5 5 5 5 5 10 10 Polymerizationinhibitor (part by mass) MDP 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1Adhesive strength (MPa) 13.9 10.8 9.8 16.3 10.7 21.2 12.8 9.5 3.7 2.8Period to removal in 20 152 283 22 26 81 140 290 5 12 warm water at 80°C. (min) Removed state*) film film film film film film film film formform form form form form form form *)Film form: a cured resin of acomposition removed in the form of a film with no adhesive residue, froma surface of glass.Materials Used

QM: dicyclopentenyl oxyethyl methacrylate (QM-657 manufactured by Rohm &Haas Co.)

BZ: benzyl methacrylate (Light Ester BZ manufactured by KyoeishaChemical Co., Ltd.)

IBX: isobornyl methacrylate (Light Ester IB-X manufactured by KyoeishaChemical Co., Ltd.)

Comparative Examples 2-1 to 2-5

Compositions were prepared in the same manner as in Example 2-1 exceptthat raw materials of types as identified in Table 2-3 were used incompositions as identified in Table 2-3. The measurement of tensileshear bond strength and the removing test were carried out in the samemanner as in Example 2-1, using the compositions prepared. Table 2-3shows the results of those.

TABLE 2-3 Comparative Example No. 2-1 2-2 2-3 2-4 2-5 (A2) component(parts by mass) TE-2000 (B2) component (parts by mass) R-684 (C2)component (parts by mass) TO-1429 M-101A 40 BZ IBX 60 30 (E2) component(parts by mass) IPA 2 Other components (parts by mass) 2-HEMA 70 MTEGMA100 70 Acryloyl morpholine 100 30 (D2) photopolymerization initiator(parts by mass) BDK 5 1.5 1.5 TPO 2.0 2.0 Polymerization inhibitor (partby mass) MDP 0.1 0.1 0.1 0.1 0.1 Adhesive strength (MPa) 10.5 2.0 2.08.4 12.3 Period to removal in not 30 30 60 not warm water at 80° C.(min) removed removed Removed state**) adhesive adhesive adhesiveresidue residue residue **)Adhesive residue: a cured resin of acomposition remained on a surface of glass, though glass was separated.Material Used

2-HEMA: 2-hydroxyethyl methacrylate

Example 2-22 and Comparative Example 2-6

The measurement of tensile shear bond strength and the removing testwere carried out in the same manner as in Example 2-1 except that thetest pieces for the removing test and for the measurement of tensileshear bond strength were prepared in such a manner that the compositionsin Example 2-1 and Comparative Example 2-5 were used and they were curedby means of a curing apparatus using an electrodeless discharge lampmanufactured by Fusion UV Systems Inc., under different accumulatedlight quantities of 500, 1000, 2000 and 4000 mJ/cm² at a wavelength of365 nm. Table 2-4 shows the results of those.

TABLE 2-4 Accumulated quantity of Composition light (mJ/cm²) No. 5001000 2000 4000 Example 2-22 Example 2-1 Adhesive 10.2 10.5 11.6 10.3strength (MPa) Period to 16 15 20 10 removal (min) ComparativeComparative Adhesive 0 0 12.3 9.8 Example 2-6 Example 2-5 strength (MPa)0 0 12.3 9.8 Period to — — not not removal (min) removed removed

Examples 2-23 and 2-24

Test pieces for the removing test were prepared using the compositionsin Examples 2-1 and 2-6 in the same manner as in Example 2-1, and theremoving test was carried out at different temperatures of 40° C., 50°C., 60° C. and 70° C. of warm water. Table 2-5 shows the results. It isclear from the results that satisfactory removability is exhibited atall the temperatures.

TABLE 2-5 Temperature of warm water Composition (° C.) No. 40 50 60 70Example 2-23 Example 2-1 Period to 353 267 185 84 removal (min) Example2-24 Example 2-6 Period to 192 143  99 70 removal (min)

Example 2-25

Pyrex glass with 150 mm×150 mm×2 mmt and the blue sheet glass used inExample 1-1 as dummy glass were bonded with the composition in Example2-1 and the composition was cured in the same manner as in Example 2-1.Only the Pyrex glass portion of the adhesive test piece was cut in thesize of 10 mm square by means of a dicing apparatus. No dropping of thePyrex glass occurred during cutting, so as to demonstrate goodprocessability. The adhesive test piece with the Pyrex glass portiononly being cut was immersed in warm water at 80° C. and the entireadhesive was removed in 60 minutes. In addition, ten cut test piecesafter removed were arbitrarily selected and taken, and the back side(the side temporarily fixed with the composition) of each cut test piecewas observed with an optical microscope, to measure a maximum width ofchip portions of glass, and to calculate an average value and a standarddeviation thereof. Table 2-6 shows the results.

TABLE 2-6 Maximum of chips on the back side of ten cut test pieces (μm)Cut test piece No. Standard 1 2 3 4 5 6 7 8 9 10 Average deviationExample 2-25 54 44 45 41 52 56 39 45 47 46 46.9 5.2 Comparative 44 51 7052 47 42 49 50 59 51 51.5 7.6 Example 2-7 Comparative 80 93 75 103 84 9276 99 109 118 92.9 13.7 Example 2-8

COMPARATIVE EXAMPLE 2-7

A hot-melt type adhesive (ADFIX A manufactured by NIKKA SEIKO CO., LTD.)was heated to melt at 90° C., to bond a 150 mm×150 mm×2 mmt Pyrex glassand the blue sheet glass used in Example 1-1. Only the Pyrex glassportion of the bonded test piece was cut in the size of 10 mm square bymeans of a dicing apparatus. No dropping of the Pyrex glass occurredduring cutting, so as to demonstrate good processability. The test piecewas immersed in an N-methylpyrrolidone solution for one day and then cuttest pieces were collected. In the same manner as in Example 2-25, tencut test pieces after removed were arbitrarily selected and the backside (the side temporarily fixed with the hot-melt type adhesive) ofeach cut test piece was observed with an optical microscope, to measurea maximum width of chip portions of glass, and to calculate an averagevalue and a standard deviation thereof. Table 2-6 shows the results.

Comparative Example 2-8

A 150 mm×150 mm×2 mmt Pyrex glass was bonded with a UV-curable PETadhesive tape. Only the Pyrex glass portion of the bonded test piece wascut in the size of 10 mm square by means of a dicing apparatus. Theadhesive tape portion of the test piece was irradiated with ultravioletrays, to reduce the adhesive strength, and then cut test pieces werecollected. In the same manner as in Example 2-25, ten cut test piecesafter removed were arbitrarily selected and the back side (the sidetemporarily fixed with the adhesive tape) of each cut test piece wasobserved with an optical microscope, to measure a maximum width of chipportions of glass, and to calculate an average value and a standarddeviation thereof. Table 2-6 shows the results.

Example 2-26 and Comparative Examples 2-9 and 2-10

The resin compositions of Example 2-1 and Comparative Examples 2-5 and2-6 were used herein and the resin compositions were cured in a shape of30 mm×10 mm×1 mmt by means of a curing apparatus using an electrodelessdischarge lamp, manufactured by Fusion UV Systems Inc., under anaccumulated light quantity of 4000 mJ/cm² at a wavelength of 365 nm. Aninitial weight of each cured resin was measured, and then it wasimmersed in water at 25° C. for 24 hours. Thereafter, the weight of eachcured resin was measured. A degree of swelling of each composition wascalculated in accordance with [degree of swelling (%)={(weight of thecured resin after immersed−initial weight of the cured resin)/initialweight of the cured resin}×100], and the results of the calculation areshown in Table 2-7. It is clear from the results that the composition ofExample 2-1 is hardly affected by cutting water used in processingbecause the degree of swelling is low after immersed in water at 25° C.,as compared with the resin compositions using the hydrophilic(meth)acrylate as in Comparative Examples.

TABLE 2-7 Degree of Composition No. swelling Example 2-26 Example 2-10.8 Comparative Comparative Example 100 Example 2-9 2-5 ComparativeComparative Example Impossible to Example 2-10 2-6 measure because ofdissolution

Example 3-1

A composition was prepared by adding 1.5 parts by mass of BDK as thephotopolymerization initiator of (D3) and 0.1 part by mass of MDP as thepolymerization inhibitor to a total amount of 100 parts consisting of 35parts by mass of SHIKOH UV-7000B (manufactured by Nippon SyntheticChemical Industry Co., Ltd., hereinafter abbreviated as UV-7000B”) asthe urethane (meth)acrylate of (A3), 40 parts by mass ofn-acryloyloxyethyl hexahydrophthalimide (TO-1429 manufactured byTOAGOSEI CO., LTD., hereinafter abbreviated as “TO-1429”) as then-(meth)acryloyloxyalkyl hexahydrophthalimide of (B3), 5 parts by massof ω-carboxy-polycaprolactone mono(meth)acrylate (ARONIX M-5300manufactured by TOAGOSEI CO., LTD., hereinafter abbreviated as “M-5300”)as the carboxyl group-containing (meth)acrylate and 20 parts by mass ofphenoxy ethyl acrylate (Light Acrylate PO-A manufactured by KyoeishaChemical Co., Ltd., hereinafter abbreviated as “PO-A”) as the(meth)acrylic acid derivative monomer having the general formula (C3).The measurement of tensile shear bond strength and the removing testwere carried out using the compositions prepared. Table 3-1 shows theresults of those.

TABLE 3-1 Example No. 3-1 3-2 3-3 3-4 3-5 3-6 3-7 (A3) component (partsby mass) UV-7000B 35 20 35 EBECRYL 2001 35 35 50 20 (B3) component(parts by mass) TO-1429 40 55 40 40 25 25 55 M-5300 5 5 5 5 20 5 5 PO-A20 20 20 20 20 20 M-5700 20 (D3) photopolymerization initiator (parts bymass) BDK 1.5 1.5 1.5 1.5 1.5 1.5 TPO 1.5 Polymerization inhibitor (partby mass) MDP 0.1 0.1 0.1 0.1 0.1 0.1 Adhesive strength 15.9 13.3 18.113.4 13.8 12.1 14.2 (MPa) Period to removal in 60 100 150 78 120 87 55warm water at 80° C. (min) Removed state*) film film film film film filmfilm form form form form form form form *)Film form: a cured resin of acomposition removed in the form of a film with no adhesive residue, froma surface of glass.

Examples 3-2 to 3-5

Compositions were prepared in the same manner as in Example 3-1 exceptthat raw materials of types as identified in Table 3-1 were used incompositions as identified in Table 3-1. The measurement of tensileshear bond strength and the removing test were carried out in the samemanner as in Example 3-1, using the compositions prepared. Table 3-1shows the results of those.

Materials Used

EBECRYL 2001: water-soluble urethane acrylate (EBECRYL 2001 Manufacturedby Daicel UCB Co., Ltd.)

M-5700: 2-hydroxy-3-phenoxypropyl acrylate (ARONIX M-5700 manufacturedby TOAGOSEI CO., LTD.)

Comparative Examples 3-1 to 3-5

Compositions were prepared in the same manner as in Example 3-1 exceptthat raw materials of types as identified in Table 3-2 were used incompositions as identified in Table 3-2. The measurement of tensileshear bond strength and the removing test were carried out in the samemanner as in Example 3-1, using the compositions prepared. Table 3-2shows the results of those.

TABLE 3-2 Comparative Example No. 3-1 3-2 3-3 3-4 3-5 (A3) component(parts by mass) UV-7000B 25 5 5 (B3) component (parts by mass) TO-142910 70 5 M-5300 55 5 5 PO-A 10 20 85 MTEGMA 70 Other components Acryloylmorpholine 100 30 (D3) photopolymerization initiator (parts by mass) BDK1.5 1.5 1.5 1.5 TPO 2.0 Polymerization inhibitor (part by mass) MDP 0.10.1 0.1 0.1 0.1 Adhesive strength 11.1 17.0 5.1 2.0 8.4 (MPa) Period toremoval not not not 30 60 in warm water at removed removed removed 80°C. (min) Removed state**) — — — adhesive adhesive residue residue**)Adhesive residue: a cured resin of a composition remained on asurface of glass, though glass was separated.

Example 3-8

Pyrex glass with 150 mm×150 mm×2 mmt and the blue sheet glass used inExample 3-1 as dummy glass were bonded with the composition in Example3-1 and the composition was cured in the same manner as in Example 3-1.

Only the Pyrex glass portion of the adhesive test piece was cut in thesize of 10 mm square by means of a dicing apparatus. Neither droppingnor loss of the Pyrex glass occurred during cutting, so as todemonstrate satisfactory processability with good chipping resistance.The adhesive test piece with the Pyrex glass portion only being cut wasimmersed in warm water at 80° C. and the entire adhesive removed in 120minutes.

INDUSTRIAL APPLICABILITY

The resin composition of the present invention has the photocurableproperty by virtue of its composition and is cured with visible light orultraviolet rays, and the cured resin thereof shows a high adhesivestrength without being affected by cutting water, and thus provides theeffects of inducing little displacement during processing of a memberand readily obtaining a member excellent in dimensional accuracy.Furthermore, it is characterized in that it reduces the adhesivestrength through contact with warm water to reduce the bonding strengthbetween members or between a member and a jig, thus enabling a member tobe readily removed. Therefore, it is industrially useful as an adhesivefor temporary fixation of optical lenses, prisms, arrays, siliconwafers, semiconductor packaging parts, and so on.

Since the method for temporarily fixing a member according to thepresent invention uses the above-mentioned characteristic composition,it is unnecessary to use an organic solvent, which used to be needed inthe conventional technologies, and the composition can be recovered inthe form of a film from a member, thereby presenting the feature of theexcellent workability. By virtue of the characteristics, the presentinvention is extremely useful from the industrial viewpoint.

The entire disclosures of Japanese Patent Application No. 2005-110798filed on Apr. 7, 2005, Japanese Patent Application No. 2005-110799 filedon Apr. 7, 2005 and Japanese Patent Application No. 2005-78298 filed onMar. 18, 2005 including the specification, claims, drawings and summaryare incorporated herein by reference in their entireties.

1. A composition comprising (A1): a (meth)acrylate with a molecularweight of at least 500 having at least one (meth)acryloyl group at aterminal or in a side chain of a molecule, wherein (A1) is selected fromthe group consisting of 1,2-polybutadiene-terminated urethane(meth)acrylates, and 1,4-polybutadiene-terminated urethane(meth)acrylates, (B1): a polyfunctional (meth)acrylate, (C1): a(meth)acrylate other than said (A1) and (B1), wherein (C1) is at leastone (meth)acrylic acid derivative monomer selected from the groupconsisting of phenol 2-mol ethylene oxide-modified (meth)acrylate,n-(meth)acryloyloxyalkyl hexahydrophthalimides, and (meth)acrylic acidderivative monomers represented by general formula (C3):Z—O—(R₂O)_(P)—R₁  General Formula (C3) wherein Z represents a(meth)acryloyl group, R₁ is a phenyl group or a phenyl group having analkyl group with 1 to 3 carbon atoms, R₂ is —C₂H₄—, —C₃H₆—,—CH₂CH(CH₃)—, —CH₂CH(OH)CH₂—, —C₄H₈— or —C₆H₁₂—, and p an integer offrom 1 to 10, and (D1): a photopolymerization initiator.
 2. Thecomposition according to claim 1, wherein (A1), (B1) and (C1) are allhydrophobic.
 3. The composition according to claim 1, comprising from 5to 80 parts by mass of (A1), from 1 to 50 parts by mass of (B1), from 5to 80 parts by mass of (C1) and from 0.1 to 20 parts by mass of (D1). 4.A composition comprising (A2): a (meth)acrylate with a molecular weightof at least 500 having at least one (meth)acryloyl group at a terminalor in a side chain of a molecule, wherein (A2) is selected from thegroup consisting of 1,2-polybutadiene-terminated urethane(meth)acrylates, and 1,4-polybutadiene-terminated urethane(meth)acrylates, (B2): a polyfunctional (meth)acrylate, (C2): a(meth)acrylate other than said (A2) and (B2), wherein (C1) is at leastone (meth)acrylic acid derivative monomer selected from the groupconsisting of phenol 2-mol ethylene oxide-modified (meth)acrylate,n-(meth)acryloyloxyalkyl hexahydrophthalimides, and (meth)acrylic acidderivative monomers represented by general formula (C3):Z—O—(R₂O)_(P)—R₁  General Formula (C3) wherein Z represents a(meth)acryloyl group, R₁ is a phenyl group or a phenyl group having analkyl group with 1 to 3 carbon atoms, R₂ is —C₂H₄—, —C₃H₆—,—CH₂CH(CH₃)—, —CH₂CH(OH)CH₂—, —C₄H₈— or —C₆H₁₂—, and p an integer offrom 1 to 10, (D2): a photopolymerization initiator and (E2): a polarorganic solvent.
 5. The composition according to claim 4, wherein (E2)is at least one member selected from the group consisting of methanol,ethanol, isopropyl alcohol and n-butanol.
 6. The composition accordingto claim 4, wherein (A2), (B2) and (C2) are all hydrophobic.
 7. Thecomposition according to claim 4, comprising from 1 to 50 parts by massof (A2) and (B2), from 5 to 95 parts by mass of (C2), from 0.1 to 20parts by mass of (D2) and from 0.5 to 10 parts by mass of (E2).
 8. Anadhesive comprising the composition according to claim
 1. 9. A methodfor temporarily fixing a member, comprising bonding to temporarily fixthe member with use of the composition according to claim 1, processingthe temporarily fixed member, and immersing the processed temporarilyfixed member in warm water of at most 90° C., thereby removing a curedresin of the composition.